[1]} define FLOW as a sequence of latent topic representations computed based on question-passage context.
Take the BiDAF model as an example, such topic representations are the integrated contextual vectors of dialog turns.
A naïve implementation of FLOW is to read the context in order and process the dialog turns sequentially, then pass the output hidden vectors from each integration layer during the \((M-1)\) -th dialog turn to the corresponding integration layer for \(Q_M\) . This process is highly nonparallel. Thus, training a CMC reader on large amounts of training dialogs can be prohibitively expensive.
